Japanese encephalitis vaccine is a vaccine that protects against Japanese encephalitis. The vaccines are more than 90% effective. The duration of protection with the vaccine is not clear but its effectiveness appears to decrease over time. Doses are given either by injection into a muscle or just under the skin.
It is recommended as part of routine immunizations in countries where the disease is a problem. One or two doses are given depending on the version of the vaccine. Extra doses are not typically needed in areas where the disease is common. In those with HIV/AIDS or those who are pregnant an inactivated vaccine should be used. Immunization of travellers who plan to spend time outdoors in areas where the disease is common is recommended.
The vaccines are relatively safe. Pain and redness may occur at the site of injection. From Wikipedia